Do more research. A lot of people ditch the whole sequential turbo setup and go single. Why? Horrible torque drop between the first turbo running out of puff and the second one taking over. Like, barely-driveable kind of horrible. As BAC5.2 mentioned, the twin-turbo crap doesn't fit with LHD anyway.
Terrible things like this don't happen where I come from. Other terrible things happen instead.
Obligatory 'build thread